The present invention relates to a method and apparatus for processing a polluted gas containing harmful substances such as various organic pollutants, malodorous components and bacteria to make the polluted gas harmless, and more particularly to a method and apparatus for processing a polluted gas containing harmful substances with ozone to make the polluted gas harmless at a high efficiency.
An oxidizing treatment with ozone is known in the art as a method of processing a polluted gas containing, for example, various organic pollutants, malodorous components, and/or bacteria, to make the polluted gas harmless. Ozone, which is self-decomposable and, thus, is unlikely to remain in the processed gas so as to give detrimental effects to the human body, is expected to be used widely in future as a clean processing agent.
For performing treatment with ozone, an ozone-containing gas from an ozone generating device (ozonizer) is injected into a polluted gas containing harmful substances. However, the concentration of the harmful substances in the polluted gas is very low in general, with the result that a large proportion of ozone is decomposed before its contribution to the decomposition by oxidation of the harmful substances and to the sterilization. It follows that ozone fails to make the polluted gas harmless at a high efficiency.
It is therefore an object of the present invention to provide a method and apparatus for efficiently processing a polluted gas containing harmful substances such as various organic pollutants, malodorous components and/or bacteria, using ozone which is an oxidizing agent having a high safety.
The above object and other objects which will be become apparent from the following description are achieved according to the present invention by a method of processing a polluted gas containing harmful substances, comprising the steps of mixing ozone with a polluted gas containing harmful substances, and allowing the ozone-mixed polluted gas to flow through an adsorbing layer containing a high-silica adsorbent which adsorbs not only ozone, but also the harmful substances, thereby making the harmful substances harmless within the adsorbing layer by the action of the ozone.
The present invention also provides an apparatus for processing a polluted gas containing harmful substances, comprising an adsorber having an adsorbing layer arranged therein, the adsorbing layer containing a high-silica adsorbent which adsorbs not only ozone, but also harmful substances; a polluted gas supply conduit for supplying a polluted gas containing harmful substances into the adsorber; an ozonizer; an ozone supply conduit connected to the polluted gas supply conduit, for supplying ozone from the ozonizer into the polluted gas flowing within the polluted gas supply conduit; and a discharge conduit for discharging the gas having passed through the adsorbing layer within the adsorber out of the adsorber.
In a preferred embodiment of the present invention, the high-silica adsorbent is selected from the group consisting of high-silica pentacile zeolite, dealumination faujasite, mesoporous silicate and a mixture thereof.
In another preferred embodiment of the present invention, the adsorbent layer includes a first adsorbent layer positioned on the upstream side and containing a mesoporous silicate, and a second adsorbent layer positioned on the downstream side and containing a dealumination faujasite.
In still another embodiment of the present invention, a layer of an ozone decomposing agent can be provided on the downstream side of the adsorbing layer. In this case, the gas passed through the adsorbing layer is brought into contact with the ozone decomposing agent to decompose the ozone which may be present in the gas passed through the adsorbing layer, so as not to leak the ozone into the downstream gas flow.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.